It is a K
The frame size of a Smith and Wesson model 66 is K.
The smith and Wesson model 10 has the K service frame.
K frame
It is a K-frame.
No, it is an L frame.
The Model 13 is on a K frame.
K frame
I believe it to be the K frame
Letter frame sizes are used by Smith & Wesson. Dan Wesson Firearms is no relation to S&W, and does not use a letter.
I frame
N
N frame 357 Magnum